Some cells in the adult animals do not appear to exhibit division (e.g., heart cells) and many other cells divide only occasionally. Such cells are said to be in

Options

A. `G_(1)` phase
B. `G_(2)` phase
C. `G_(0)` phase
D. S - phase

Answer

To solve the question, we need to understand the different phases of the cell cycle and identify which phase corresponds to cells that do not actively divide or divide infrequently.

### Step-by-Step Solution:

1. **Understanding Cell Division**:
- In adult animals, certain cells, such as heart cells, do not divide at all, while others may divide only occasionally.

2. **Identifying the Phases of the Cell Cycle**:
- The cell cycle consists of several phases: G1 phase, S phase, G2 phase, and M phase (mitosis).
- Each of these phases has specific functions related to cell growth and division.

3. **Analyzing the Options**:
- **G1 Phase**: This is the first phase of the cell cycle where the cell grows and prepares for DNA replication. Cells are actively preparing to divide, so this option does not fit.
- **S Phase**: This is the synthesis phase where DNA replication occurs. Cells are actively dividing during this phase, so this option is also incorrect.
- **G2 Phase**: This phase occurs after DNA has been replicated (during S phase) and before mitosis. Cells are preparing for division, making this option incorrect as well.
- **G0 Phase**: This is a quiescent phase where cells are not actively dividing. Cells in this phase are in a resting state and may exit the cell cycle altogether.

4. **Conclusion**:
- Since the question refers to cells that do not exhibit division (like heart cells) or divide only occasionally, the correct answer is **G0 phase**. This phase represents a state of dormancy in the cell cycle.

### Final Answer:
The correct option is **G0 phase**.

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